A kind of air supply dust removal device for preventing and controlling high temperature corrosion of coal-fired power plant boiler

Abstract

This invention provides an air supply and dust removal device for high-temperature corrosion prevention and control in coal-fired power plant boilers, comprising a cyclone separator and a microporous filter. The cyclone separator includes a separation shell, an air inlet, an exhaust outlet, and a first ash discharge outlet. The separation shell has a cylindrical separation chamber, and the air inlet, exhaust outlet, and first ash discharge outlet are respectively connected to the separation chamber. The air inlet is located at the upper part of the separation shell and is tangent to the outer wall of the separation shell. The exhaust outlet is located at the top of the separation shell, and the first ash discharge outlet is located at the bottom of the separation shell. The microporous filter includes a filter shell and a microporous filter element. The filter shell has an air inlet and an exhaust outlet, with the air inlet connected to the exhaust outlet. The microporous filter element is disposed inside the filter shell. The cyclone separator performs primary dust removal of large particles in the secondary air, and the microporous filter performs secondary dust removal of small particles in the secondary air, thereby achieving the removal of both large and small particles of dust in the secondary air.

Description

Technical Field

[0001] This invention belongs to the technical field of air supply and dust removal devices, specifically relating to an air supply and dust removal device for high-temperature corrosion prevention and control in coal-fired power plant boilers. Background Technology

[0002] To reduce NO during combustion in coal-fired power plant boilers x The generation of NO is generally achieved by using low NO content. x Combustion technology that creates a reducing atmosphere by controlling the airflow in the main combustion zone can effectively suppress NO. x This process generates high concentrations of corrosive gases such as H2S and CO near the water-cooled walls, easily leading to high-temperature corrosion. Coupled with the power plant's co-firing of high-sulfur coal and the normalized deep peak-shaving operation of the power grid, the problem of high-temperature corrosion of the water-cooled walls becomes increasingly serious, easily leading to thinning of the tube walls, leakage, and even tube rupture, severely threatening the safe and stable operation of the unit.

[0003] Porous wall-mounted air supply and wall-adhesive air supply technologies, which utilize a dedicated supply of 350°C high-temperature secondary air near the water-cooled wall to form an air film on the pipe wall surface, isolating corrosive media from contact with the water-cooled wall, have gradually become effective measures for high-temperature corrosion control. However, the dedicated secondary air supply often has a high dust content, and the high-speed, dust-laden airflow continuously erodes and wears the nozzles, significantly reducing their service life and causing the air film to fail, resulting in a substantial decrease in corrosion control effectiveness. Therefore, there is an urgent need for an air supply dust removal device that reduces the amount of dust in the supplied air. Summary of the Invention

[0004] The embodiments of the present invention aim to at least solve one of the technical problems existing in the prior art, and provide an air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers.

[0005] An embodiment of the present invention provides an air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers, including a cyclone separation mechanism and a microporous filtration mechanism; The cyclone separation mechanism includes a separation shell, an air inlet, an exhaust outlet, and a first ash discharge outlet. The separation shell has a cylindrical separation cavity. The air inlet, the exhaust outlet, and the first ash discharge outlet are respectively connected to the separation cavity. The air inlet is located at the upper part of the separation shell and is tangent to the outer wall of the separation shell. The exhaust outlet is located at the top of the separation shell, and the first ash discharge outlet is located at the bottom of the separation shell. The microporous filtration mechanism includes a filter housing and a microporous filter element. The filter housing has an air inlet and an air outlet. The air inlet is connected to the air outlet. The microporous filter element is disposed inside the filter housing.

[0006] In some embodiments of the present invention, the microporous filtration mechanism further includes a first support plate and a second support plate; The first support plate and the second support plate are fixedly spaced within the filter housing. The first support plate and the second support plate divide the accommodating space of the filter housing into a first space, a second space and a third space that are connected in sequence. The air inlet is connected to the first space and the exhaust port is connected to the third space. The microporous filter element is disposed in the second space.

[0007] In some embodiments of the present invention, the microporous filter element is detachably connected to the first support plate and the second support plate.

[0008] In some embodiments of the present invention, a plurality of microporous filter elements are provided in the second space, and the plurality of microporous filter elements are spaced apart and uniformly distributed in the second space.

[0009] In some embodiments of the present invention, the diameter ratio of the microporous filter element to the filter housing is 1:10 to 3:10.

[0010] In some embodiments of the present invention, the first support plate and the second support plate are respectively provided with a plurality of spaced and uniformly distributed through holes.

[0011] In some embodiments of the present invention, the bottom of the filter housing is provided with a second ash discharge port, which is connected to the first space.

[0012] In some embodiments of the present invention, the top of the filter housing is provided with a pulse backflush port, which is connected to the third space.

[0013] In some embodiments of the present invention, the separation shell further includes a conical ash collection cavity, which is connected to the separation cavity and located at the bottom of the separation cavity, and the first ash discharge interface is connected to the separation cavity through the ash collection cavity.

[0014] In some embodiments of the present invention, the system further includes a dynamic air conditioning mechanism, which includes an air conditioning duct, an air volume sensor, an air pressure sensor, an electric regulating damper, and a servo actuator. One end of the air regulating pipe is connected to the exhaust port, and the other end of the air regulating pipe is used to connect to the air inlet of the boiler. The air volume sensor, the air pressure sensor, and the servo actuator are respectively located at one end of the air regulating pipe near the exhaust port, and the electric regulating damper is located at the other end of the air regulating pipe away from the exhaust port. The servo actuator is electrically connected to the boiler's DCS system, the air volume sensor, and the air pressure sensor, respectively. The servo actuator is used to control the opening degree of the electric regulating damper according to the operating condition signal of the boiler's DCS system, the air volume of the air volume sensor, and the air pressure of the air pressure sensor.

[0015] The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to embodiments of the present invention includes a cyclone separation mechanism and a microporous filtration mechanism. The cyclone separation mechanism includes a cylindrical separation shell with a cylindrical separation cavity. The air inlet, the exhaust, and the first ash discharge port are respectively connected to the separation cavity. Because the air inlet is tangent to the outer wall of the cylindrical separation shell, the secondary air enters the cylindrical separation chamber through the air inlet, forming a highly uniform vortex. This vortex moves downwards along the inner wall of the separation chamber. Large dust particles in the secondary air are thrown towards the inner wall of the separation chamber under centrifugal force. After colliding with the inner wall, the large dust particles slide down to the first ash discharge port and are discharged from the cyclone separator. The secondary air, having had its large dust particles removed, moves upwards in the central area of ​​the cylindrical separation chamber, reaching the top of the separation shell and being discharged into the filter shell through the exhaust port. Inside the filter shell, the secondary air undergoes filtration by a microporous filter element to remove small dust particles. This small dust particles are then discharged from the exhaust port of the microporous filter mechanism and transported to the boiler. By performing primary dust removal of large dust particles in the secondary air through the cyclone separator and secondary dust removal of small dust particles through the microporous filter mechanism, both large and small dust particles in the secondary air are effectively removed. This system achieves a large particle dust removal efficiency of ≥90% and an operating pressure loss of ≤300Pa under high temperature conditions of 350℃. The system also achieves a small particle dust removal efficiency of ≥99%, a dust concentration of ≤3mg / m³ after purification, and a total efficiency of ≥99.8% for the two-stage dust removal system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to an embodiment of the present invention. Figure 2 for Figure 1 A cross-sectional view of the microporous filter unit shown. Figure 3 This is a block diagram illustrating the working principle and system connection of an air supply and dust removal device for high-temperature corrosion prevention and control in coal-fired power plant boilers, according to an embodiment of the present invention.

[0017] The labels in the attached diagram are as follows: 1. Cyclone separator; 101. Air inlet; 102. Exhaust outlet; 103. Conical ash collection chamber; 104. First ash discharge outlet; 105. Separation housing; 2. Microporous filtration mechanism; 201. Microporous filter element; 202. Pulse backflushing interface; 203. First support plate; 204. Second support plate; 205. Filter housing; 206. Air inlet; 207. Exhaust port; 208. Second ash discharge interface; 21. First space; 22. Second space; 23. Third space; 24. Small particle ash collection chamber; 3. Dynamic air conditioning mechanism; 301. Air volume sensor; 302. Air pressure sensor; 303. Electric regulating damper; 304. Servo actuator; 305. Air duct. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit disclosure. The described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0019] like Figures 1 to 3 As shown, an embodiment of the present invention provides an air supply dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers, including a cyclone separation mechanism 1 and a microporous filtration mechanism 2. The air separation mechanism includes a separation housing 105, an air inlet 101, an exhaust port 102, and a first ash discharge port 104. The separation housing 105 has a cylindrical separation chamber. The air inlet 101, the exhaust port 102, and the first ash discharge port 104 are respectively connected to the separation chamber. The air inlet 101 is located at the upper part of the separation housing 105 and is tangent to the outer wall of the separation housing 105. The exhaust port 102 is located at the top of the separation housing 105, and the first ash discharge port 104 is located at the bottom of the separation housing 105. The microporous filtration mechanism 2 includes a filter housing 205 and a microporous filter element 201. The filter housing 205 has an air inlet 206 and an exhaust outlet 207. The air inlet 206 is connected to the exhaust outlet 102. The microporous filter element 201 is disposed inside the filter housing 205.

[0020] The present invention provides an air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers, which includes a cyclone separation mechanism 1 and a microporous filtration mechanism 2. The cyclone separation mechanism 1 includes a cylindrical separation shell 105, which has a cylindrical separation cavity. An air inlet 101, an exhaust 102, and a first ash discharge 104 are respectively connected to the separation cavity. Since the air inlet 101 is tangent to the outer wall of the cylindrical separation housing 105, the secondary air enters the cylindrical separation chamber through the air inlet 101, forming a highly uniform vortex. The secondary air then moves downward along the inner wall of the separation chamber. Large dust particles in the secondary air are thrown towards the inner wall of the separation chamber under the action of centrifugal force. After colliding with the inner wall, the large dust particles slide down the inner wall to the first ash discharge port 104, and are discharged from the cyclone separation mechanism 1. The secondary air that has removed large dust particles moves upward in the central area of ​​the cylindrical separation chamber, moves to the top of the separation housing 105, and is discharged into the filter housing 205 through the exhaust port 102. The secondary air that has removed large dust particles passes through the microporous filter element 201 in the filter housing 205 to remove small dust particles. The secondary air that has removed small particles is discharged from the exhaust port of the microporous filter mechanism and transported to the boiler.

[0021] The system removes large dust particles from the secondary air through a cyclone separator 1, followed by a microporous filter 2 to remove small dust particles. This achieves the removal of both large and small dust particles in the secondary air. Under high-temperature conditions of 350℃, the system achieves a large particle removal efficiency of ≥90%, an operating pressure loss of ≤300Pa, a small particle removal efficiency of ≥99%, a post-purification dust concentration of ≤3mg / m³, and a total two-stage dust removal efficiency of ≥99.8%.

[0022] In some embodiments of the present invention, the separating housing 105 further includes a conical dust collection chamber 103, which communicates with the separating chamber and is located at the bottom of the separating chamber. The first dust discharge port 104 communicates with the separating chamber through the conical dust collection chamber 103. By providing a conical dust collection chamber 103 communicating with the bottom of the separating chamber, large dust particles can fall into the conical dust collection chamber 103 for easy collection. Specifically, the conical dust collection chamber 103 has a first end and a second end arranged opposite to each other. The first end of the conical dust collection chamber 103 communicates with the separating chamber, and the second end of the conical dust collection chamber 103 communicates with the exhaust port 102. The diameter of the first end is larger than the diameter of the second end, and the taper of the conical dust collection chamber 103 is 60°~70°. This taper range allows large dust particles to slide to the exhaust port 102. Preferably, the taper of the conical dust collection chamber 103 is 65°.

[0023] In some embodiments of the present invention, the microporous filter mechanism 2 further includes a first support plate 203 and a second support plate 204. The first support plate 203 and the second support plate 204 are fixedly spaced within the filter housing 205. The first support plate 203 and the second support plate 204 divide the accommodating space of the filter housing 205 into a first space 21, a second space 22 and a third space 23 that are connected in sequence. The air inlet 206 is connected to the first space 21, the exhaust port 207 is connected to the third space 23, and the microporous filter element 201 is disposed in the second space 22. After the secondary air passes through the cyclone separator 1 to separate large dust particles, it is discharged from the exhaust port 102 of the cyclone separator 1, flows through the connecting pipe into the air inlet 206, and enters the first space 21 of the filter housing 205 through the air inlet 206. The secondary air with large dust particles removed enters the second space 22 equipped with a microporous filter element 201 from the first space 21. The microporous filter element 201 adsorbs small dust particles in the secondary air to remove them. The secondary air with small dust particles removed enters the third space 23 from the second space 22 and is discharged into the boiler or to the dynamic air regulating mechanism 3 through the exhaust port 207 connected to the third space 23.

[0024] In some embodiments of the present invention, a microporous filter element 201 is supported between a first support plate 203 and a second support plate 204. The microporous filter element 201 has a first end and a second end disposed opposite to each other. The first end of the microporous filter element 201 is detachably connected to the first support plate 203, and the second end of the microporous filter element 201 is detachably connected to the second support plate 204. By making the microporous filter element 201 detachable from the first support plate 203 and the second support plate 204, the microporous filter element 201 can be replaced, thus saving costs. Specifically, the detachable method can be a threaded connection, a snap-fit ​​connection, an interference fit, etc.

[0025] In some embodiments of the present invention, a plurality of microporous filter elements 201 are provided in the second space 22, and the plurality of microporous filter elements 201 are spaced apart and evenly distributed in the second space 22. By setting a plurality of spaced and evenly distributed microporous filter elements 201, the filtration efficiency of the microporous filtration mechanism 2 can be improved, and the removal of small particulate dust from the secondary air can be more uniform.

[0026] In some embodiments of the present invention, the diameter ratio of the microporous filter element 201 to the filter housing 205 is 1:10 to 3:10. Within this diameter ratio range, the microporous filter element 201 exhibits good removal effect on secondary air. Preferably, the diameter ratio of the microporous filter element 201 to the filter housing 205 is 1:5. This diameter ratio ensures that the microporous filter element 201 achieves the best removal effect on secondary air while also considering the wind speed of the secondary air. Furthermore, the filtration accuracy of the microporous filter element 201 is 5–15 μm.

[0027] In some embodiments of the present invention, the first support plate 203 is provided with a plurality of spaced and evenly distributed through holes, which connect the first space 21 and the second space 22. The second support plate 204 is provided with a plurality of spaced and evenly distributed through holes, which connect the second space 22 and the third space 23.

[0028] In some embodiments of the present invention, a pulse backflushing interface 202 is provided on the top of the filter housing 205, and the pulse backflushing interface 202 is connected to the third space 23. Air is blown into the third space 23 in a pulsed manner through the pulse backflushing interface 202. The pulsed air enters the second space 22 from the third space 23 to blow off small dust particles adhering to the microporous filter element 201. The small dust particles enter the first space 21 from the second space 22 through multiple through holes on the first support plate 203. The pulse backflushing interface allows for online cleaning of the microporous filter element 201, preventing clogging and extending the replacement interval.

[0029] In some embodiments of the present invention, a second dust discharge port 208 is provided at the bottom of the filter housing 205, and the second dust discharge port 208 communicates with the first space 21. Specifically, the filter housing 205 also has a small particle dust collection chamber 24 communicating with the first space 21. The small particle dust collection chamber 24 is located at the bottom of the first space 21, and the second dust discharge port 208 is located at the bottom of the small particle dust collection chamber 24. The second pulse blowing blows off the small particle dust adhering to the microporous filter element 201. The small particle dust enters the first space 21 from the second space 22, enters the small particle dust collection chamber 24 from the first space 21, and is discharged through the second dust discharge port 208 at the bottom of the small particle dust collection chamber 24. The second dust discharge port 208 can be connected to a dust storage device for centralized treatment of small particle dust. The small particle dust collection chamber 24 is a conical mechanism, and the structure of the small particle dust collection chamber 24 is the same as that of the conical dust collection chamber 103.

[0030] In some embodiments of the present invention, the system further includes a dynamic air regulating mechanism 3, which includes an air regulating duct 305, an air volume sensor 301, an air pressure sensor 302, an electrically adjustable damper 303, and a servo actuator 304. One end of the air regulating duct 305 is connected to the exhaust port 207, and the other end of the air regulating duct 305 is used to connect to the air inlet of the boiler. The air volume sensor 301, the air pressure sensor 302, and the servo actuator 304 are respectively located at the end of the air regulating duct 305 near the exhaust port 207, and the electrically adjustable damper 303 is located at the end of the air regulating duct 305 away from the exhaust port 207. The servo actuator 304 is electrically connected to the boiler's DCS system, the air volume sensor 301, and the air pressure sensor 302, respectively. The servo actuator 304 is used to control the opening degree of the electrically adjustable damper 303 according to the operating condition signal of the boiler's DCS system, the air volume of the air volume sensor 301, and the air pressure of the air pressure sensor 302. The servo actuator 304 is bidirectionally connected to the boiler DCS system, receiving real-time signals from boiler load, combustion conditions, and wall temperature. Based on these signals, as well as the airflow signals from the airflow sensor 301 and the air pressure signals from the air pressure sensor 302, the servo actuator 304 automatically adjusts the opening of the electric regulating damper 303 to regulate airflow and air pressure. The airflow adjustment range is 0–100%, and the air pressure adjustment accuracy is ±50Pa. It supports manual / automatic dual-mode switching. High-temperature secondary air, after removing large and small dust particles, is delivered to the nozzles through the air supply pipeline, forming a stable protective air film on the water-cooled wall surface to isolate corrosive media and prevent nozzle erosion and wear.

[0031] The system of this invention adopts an integrated modular structure for each component. The outer shell of each component is made of 350℃ special high-temperature and heat-resistant steel, and all pipeline connections use high-temperature resistant sealing flanges with flexible graphite high-temperature gaskets to ensure airtightness at 350℃. Furthermore, the system of this invention can operate stably for extended periods in an environment of 350℃.

[0032] The system of the present invention also has the following beneficial effects: It adopts tangential wall-mounted vortex flow, with no easily damaged parts, uniform flow field, low pressure loss, and simple maintenance; The diameter ratio, cone angle, and inlet parameters of the cyclone separator are optimized in a coordinated manner, achieving a coarse dust removal efficiency of ≥90% and an operating pressure loss of ≤300Pa under high temperature conditions of 350℃. The microporous filtration mechanism is matched with the cylinder and filter element in proportion, with a fine dust removal efficiency of ≥99%, a total two-stage dust removal efficiency of ≥99.8%, and a nozzle service life extended to 2-3 years; The dynamic air regulation mechanism is linked with the boiler DCS, and the air volume and pressure can be precisely adjusted to adapt to deep peak shaving and high-sulfur coal blending and other operating conditions. With its integrated modular design, it is easy to install, has good sealing performance, and is stable in operation at high temperatures, making it suitable for both new boilers and retrofitting existing boilers.

[0033] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A dust removal and air supply device for high-temperature corrosion prevention and control in coal-fired power plant boilers, characterized in that, Includes a cyclone separation mechanism and a microporous filtration mechanism; The cyclone separation mechanism includes a separation shell, an air inlet, an exhaust outlet, and a first ash discharge outlet. The separation shell has a cylindrical separation cavity. The air inlet, the exhaust outlet, and the first ash discharge outlet are respectively connected to the separation cavity. The air inlet is located at the upper part of the separation shell and is tangent to the outer wall of the separation shell. The exhaust outlet is located at the top of the separation shell, and the first ash discharge outlet is located at the bottom of the separation shell. The microporous filtration mechanism includes a filter housing and a microporous filter element. The filter housing has an air inlet and an air outlet. The air inlet is connected to the air outlet. The microporous filter element is disposed inside the filter housing.

2. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 1, characterized in that, The microporous filtration mechanism also includes a first support plate and a second support plate; The first support plate and the second support plate are fixedly spaced within the filter housing. The first support plate and the second support plate divide the accommodating space of the filter housing into a first space, a second space and a third space that are connected in sequence. The air inlet is connected to the first space and the exhaust port is connected to the third space. The microporous filter element is disposed in the second space.

3. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 2, characterized in that, The microporous filter element is detachably connected to the first support plate and the second support plate.

4. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 2, characterized in that, The second space is provided with a plurality of microporous filter elements, which are spaced apart and evenly distributed in the second space.

5. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 4, characterized in that, The diameter ratio of the microporous filter element to the filter housing is 1:10 to 3:

10.

6. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 2, characterized in that, The first support plate and the second support plate are respectively provided with a plurality of spaced and evenly distributed through holes.

7. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 2, characterized in that, The bottom of the filter housing is provided with a second ash discharge port, which is connected to the first space.

8. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 2, characterized in that, The top of the filter housing is provided with a pulse backflush port, which is connected to the third space.

9. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 1, characterized in that, The separation shell also has a conical ash collection cavity, which is connected to the separation cavity and located at the bottom of the separation cavity. The first ash discharge port is connected to the separation cavity through the ash collection cavity.

10. The air supply and dust removal device for high-temperature corrosion prevention and control of coal-fired power plant boilers according to claim 1, characterized in that, The system also includes a dynamic air conditioning mechanism, which includes an air conditioning duct, an air volume sensor, an air pressure sensor, an electric regulating damper, and a servo actuator. One end of the air regulating pipe is connected to the exhaust port, and the other end of the air regulating pipe is used to connect to the air inlet of the boiler. The air volume sensor, the air pressure sensor, and the servo actuator are respectively located at one end of the air regulating pipe near the exhaust port, and the electric regulating damper is located at the other end of the air regulating pipe away from the exhaust port. The servo actuator is electrically connected to the boiler's DCS system, the air volume sensor, and the air pressure sensor, respectively. The servo actuator is used to control the opening degree of the electric regulating damper according to the operating condition signal of the boiler's DCS system, the air volume of the air volume sensor, and the air pressure of the air pressure sensor.

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